Fix web app failing to display items in Chrome
Fix web app failing to display items in Chrome

The web app was detecting its environment as a Chrome
extension when run in Chrome and trying to use the Chrome Extension
Dropbox auth driver.

Make the test for the Chrome extension environment stricter
by testing for window.chrome.extension

robertknight/passcards,robertknight/passcards,robertknight/passcards,robertknight/passcards